GB722534A - Improvements in web supply apparatus - Google Patents

Abstract

722,534. Feeding webs. SCHNELLPRESSENFABRIK FRANKENTHAL ALBERT & CIE AKT.-GES. Feb. 7, 1952 [Feb. 14, 1951], No. 3212/52. Class 100 (1). [Also in Group XL (b)] An apparatus for splicing the free end of a new paper web roll to the expiring end of an exhausted roll being fed to a machine fed with paper web, includes a device wherein, through a control element, the rotation of the new roll controls the intensity of a beam of light falling on a photo-electric cell responsive thereto, the cell being connected, through an amplifier, to actuate relays and cause electromagnets to effect splicing and subsequent severing of the webs by a brush and knife respectively. A roll-supporting spider comprises arms, 7 ... 12, which support paper rolls 19, 20 and 21. The arms 7, 8, 9 are carried by a support 5, while the arms 10, 11, 12 are carried by a support 6, the supports 5 and 6 being axially displaceable along a shaft so as to accommodate rolls of varying width. The replacement roll 20 is accelerated to the linear speed of the web 29, unwound from the expiring roll 21, by means of a belt 22 mounted on a frame 28 and driven from the printing machine. The frame 28 is lowered prior to a splicing operation by a lever 73 actuated by a crank-pin 72 rotated by gearing 70, 68 having a ratio corresponding to the number of paper rolls carried by the spider, i.e. 1 : 3 in the present case. A pulley 48 having a reflecting surface with a darkened part 49 is mounted on spindles supporting one end of each roll. The pulley 48 thus reflects a light beam from a light source 50 to a photoelectric cell 51 until the part 49 interrupts such reflection, the part 49 being circumferentially spaced a predetermined distance from the free end 35 of the roll 20. When a switch in the photo-electric cell 51 circuit is closed, the part 49, due to the interruption in the light beam, causes the cell 51 to release a current impulse, which when amplified, operates in succession two electromagnets 41 and 47. The electromagnet 41 displaces a web deflecting brush 37 through a rod 40 and lever 39, while the electromagnet 47 actuates a web-severing knife 42 through a rod 46. The expiring rolls 20, 21, 22 are braked during unwinding by a band 61 engaging a brake disc 60, the band 61 being tensioned by a bell-crank lever 65 one arm 66 of which carries a weight 67, while the other arm 63 is secured to the band 61. The weight 67 only causes braking during downward movement, i.e. during unwinding of the rolls.